ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Polymer and Materials Science  (49)
  • Animals  (4)
  • MATERIALS, NONMETALLIC  (3)
  • 1980-1984  (39)
  • 1965-1969  (17)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 1629-1638 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Blends of poly(ethylene terephthalate) (PET) and a copolyester of bisphenol A-terephthaloylisophthaloyl (PAr) (2:1:1) have been studied both before and after transesterification. The physical blends exhibit phase separation in their amorphous states: a pure PET phase and a mixed PAr-rich phase. In spite of this phase separation, PET crystallinity in blends, normalized to PET fraction, surprisingly goes through a maximum at 25% PAr content. The transesterfied copolymers are noncrystallizable and exhibit a single Tg between those of starting polymers, PET and PAr.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 10 (1966), S. 1617-1623 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The n-alkyl α-cyanoacrylates from methyl through n-octyl exhibit a reverse order of polymerization rate on biological substrates compared to that on water. On water, the lower homologs spread and polymerize rapidly, whereas the higher homologs spread but polymerize slowly. On biological substrates, the lower homologs do not spread or spread slightly and the higher homologs exhibit large spreadabilities and very rapid polymerization rates. Determination of the spreading coefficients for these systems by using the monomers or model compounds confirm the observed spreadabilities. It is proposed that the increased rate of polymerization of the higher homologs on biological substrates may be due to increased catalyst concentrations on these surfaces or to the solubilization of the higher homologs at the interface, making the catalyst sites more available to the monomer. The suggestion is made that if the liquid monomers spread and orient on the substrate and subsequently polymerize, the polymers will maintain the orientation. If such is the case, a technique is available for preparing stereospecific vinyl polymers which may have different spatial configurations depending on the polarity of the liquid substrate upon which they have been allowed to spread and polymerize.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 28 (1983), S. 3227-3233 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Studies have been made of the near surface photooxidation of atactic polystyrene films prepared in the absence of air. The samples were photooxidized on exposure to air at two frequencies, 254 and 365 nm, using a calibrated mercury irradiation source with filters. Most studies were made at 40°C and as a function of irradition time with the reactions characterized by changes in molecular weight and composition. The former was evaluated by gel permeation chromatography and the latter by transmission Fourier transform infrared spectroscopy and by multiple-internal-reflectance infrared spectra using different angles and different crystals to evaluate compositions as a function of film depth. Species identified in photooxidation include the generation of hydroperoxides and the appearance of carbonyl bands with the latter identified by the spectral shift asociated with the exposure of the photooxidized polystyrene surface to ammonia. These results suggest that principal products of near-surface oxidation of polystyrene are carboxylic acids.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 2307-2315 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Nuclear magnetic resonance spectroscopy has been used to study the dissociation and reaction of N,N′-(2-propyloximino)-4,4′-methylenebis(phenylcarbamate), as a crosslinking agent for polymers containing labile hydrogens. The crosslinking of poly(acrylic acid), polyacrylamide, and poly(vinyl alcohol) was found to result upon heating each to 150°C for 10 min with this component at 2-10 wt %.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 11 (1967), S. 335-340 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Gel permeation chromatography was used to follow changes in the molecular weight distribution of a polyisobutene, initial Mv = 466,000, during degradation induced by sonic irradiation. Seven samples taken at times of 200-163,500 sec. were studied. In general, a steady decrease in molecular weight was observed, although a bimodal distribution was present after 20,000 sec. irradiation. Various measures of inhomogeneity, Mw/Mn, U, etc., were examined. The function, σn/Mw, where σn is the standard deviation of the number distribution, is considered as a measure of the relative distribution. It is shown to be almost constant throughout the degradation.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 11 (1967), S. 2227-2253 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The crosslinking efficiency of sulfur in the vulcanization of natural rubber in the presence of 2-mercaptobenzothiazole, zinc oxide, and lauric acid has been determined as a function of cure time, cure temperature, and lauric acid concentration. With a low concentration of lauric acid structurally complex networks are formed, which contain 11-19 combined sulfur atoms per chemical crosslink present. The complexity increases with time of vulcanization. With a high lauric acid concentration much simpler networks are formed, which become progressively more simple as reaction proceeds (6 network-combined sulfur atoms per chemical crosslink, decreasing to 2.4 with time). Increasing the cure temperature from 100 to 140°C. reduces the efficiency of crosslinking in both cases. The changes in efficiency are attributed to the influences of the reaction variables (in particular, the concentration of rubber-soluble complexes of the zinc laurate with zinc benzothiazolyl mercaptide) on the structure and subsequent reactions of initially formed polysulfidic crosslinks.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A group of C14-tagged ethylene and propylene polymers consisting of physical mixtures of homopolymers, block copolymers made up of two homopolymer sequences, and block copolymers made up of several homopolymer segments has been studied by differential thermal analysis (DTA). The effect of randomness in copolymers has also been studied in this set of systems, which contains 0-51 wt.-% ethylene. Block copolymers and physical mixtures have been found to have thermograms with endothermal minima at approximately 138 and 163°C. The ratio of heights of the two minima has been found to be a function of the ethylene and propylene content for mixtures of homopolymers and for block copolymers without randomness. DTA thus provides an analysis for monomer ratios in physical mixtures and in block copolymers of ethylene and propylene. The cooling thermograms of block copolymers have been demonstrated to have two exotherms in all cases where the block ethylene content exceeded 10%; the propylene limit was not fixed. Mixed homopolymers do not exhibit two freezing exotherms. The total heat of fusion of the polymer has been found to be a usable measure of chain randomness and block nature. The conditions for observation of single and multiple transitions have been extended.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Vulcanization of natural rubber at 140°C. with a CBS-accelerated sulfur system of conventional type gives rise to a structurally complex network in which the number of sulfur atoms combined per chemical crosslink present increases from 12 to 21 with increasing reaction time. The complexity of the network increases with increasing temperature of vulcanization. Crosslinking of a purified synthetic cis-1,4-polyisoprene proceeds more slowly and yields a slightly more complex network. Despite this overall similarity the natural rubber vulcanizates exhibit considerably higher tensile strengths.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 11 (1967), S. 2215-2226 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A general treatment is given of the methods to be used in other parts of this series for calculating the degree of chemical crosslinking in natural rubber vulcanizates from stress-strain measurements in extension and from equilibrium volume swelling measurements. Corrections are required for the presence in the vulcanizate of appreciable quantities of particulate solids or soluble diluents and for the introduction of foreign atoms into the rubber network. For this purpose distinction is made between the rubber vulcanizate, the rubber matrix, the rubber network, and the rubber hydrocarbon component of the network. Expressions are derived, in terms of these concepts, for the Money-Rivlin parameter, C1, measured on vulcanizates which have undergone various treatments.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 11 (1967), S. 2255-2269 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The crosslinking efficiency of sulfur in the vulcanization system comprising (in parts by weight) natural rubber (100), sulfur (1.5), N-cyclohexylbenzothiazole-2-sulfenamide (2.37), zinc oxide (5), and lauric acid (1-10) is relatively insensitive to the lauric acid concentration and to the temperature of vulcanization (between 100 and 140°C.). The networks formed contain initially 8-11 combined sulfur atoms per chemical crosslink present, but this number falls progressively to about 4 as the reaction proceeds. The results are consistent with the intermediate formation of a rubber-soluble complex of cyclohexylamine with zinc benzothiazolyl mercaptide. This complex is believed to be responsible also for the further slow crosslinking which the vulcanizates undergo on standing at room temperature.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...